This invention relates to a reel spring for magnetic tape cassettes and to a method for making the spring. Reel springs are used in a cassette to rotatably mount the tape reel therein. Examples of prior art reel springs are shown in Schoettle, U.S. Pat. 4,717,091.
The manufacture of prior art springs is encumbered with certain disadvantages. Production of Schoettle,s spring occasions a certain amount of waste of the raw material. This waste is brought about by either the tip configuration used or the overall shape of the spring. In the rounded tip configuration shown in Schoettle no part of one spring adjoins the following spring in the strip of raw material and a segment of material the axial length of the tip spacing between adjacent springs is wasted.
Schoettle also suggests completely eliminating any waste or loss of raw material by simply slitting straight across the raw material to form springs which are elongated rectangles. While this is the optimum spring configuration from the standpoint of material usage, it unfortunately results in a spring of diminished utility. The problem with a completely rectangular spring is the sharp corners tend to catch or hang up on the tape reels. This operational defect of the rectangular spring, outweighs its manufacturing advantages.